The traditional automatic or semi-automatic coffee machines comprise an infusion group having an infusion cylinder reversibly movable from a disengagement position to an engagement position with a closure piston for the creation of an infusion chamber into which the infusion water is conveyed which has been heated by a boiler, and conveyed through a suitable inner channelling to the closure piston.
The infusion cylinder instead has at its interior an expulsion piston which is moved in a coordinated manner with a scraper for the discharge of the load of spent coffee powder.
A functioning cycle in general comprises a step of loading the coffee powder load inside the infusion cylinder, a step of outgoing movement of the infusion cylinder towards the engagement position with the closure piston for the creation of the infusion chamber and the achievement of the infusion, and a step of return movement of the infusion cylinder which is disengaged from the closure piston for expelling the load of spent coffee powder and loading the new coffee powder load.
Such coffee machines can lament an excessive bulk due to the particular placement and structure of the infusion group and mechanisms with which it is equipped.
The increasingly heard market need to have the infusion cylinder dismountable, to be removed mainly for its cleaning and/or maintenance, has in general led to an increased structural complication of the infusion group.